//fpnotebook.com/
Central Retinal Artery Occlusion
Aka: Central Retinal Artery Occlusion, CRAO, Branch Retinal Artery Occlusion, BRAO, Acute Retinal Ischemia- See Also
- Definitions
- Central Retinal Artery Occlusion (CRAO)
- Central Retinal artery is occluded affecting all Visual Fields
- Branch Retinal Artery Occlusion (BRAO)
- Branches of central Retinal artery are occluded, with segmental Vision Loss
- Central Retinal Artery Occlusion (CRAO)
- Epidemiology
- Annual Incidence: One per 100,000 (U.S.)
- Age (mean): 60 years old
- Pathophysiology
- Typically due to embolism to the Retinal artery
- May also occur due to thrombosis, inflammation or Eye Trauma
- Arteritis (e.g. Temporal Arteritis) accounts for <5% of cases
- Typically due to embolism to the Retinal artery
- Risk Factors
- Age over 70 years
- Cardiovascular disease risks
- Migraine Headaches
- Collagen vascular disease (e.g. Systemic Lupus Erythematosus)
- Temporal Arteritis
- Sickle Cell Anemia
- Causes: Ophthalmic artery Occlusion
- See Transient Ischemic Attack
- Cholesterol emboli
- Thrombotic emboli
- Vasculitis
- Hypoperfusion
- Hemodialysis
- Severe shock
- Nocturnal artery Hypotension (awake with Vision Loss)
- Associated with antihypertensives taken near bedtime
- Symptoms
- See Transient Monocular Blindness (Amaurosis Fugax)
- Painless acute unilateral Vision Loss
- More than half of patients have only hand motion and light perception
- CRAO causes Vision Loss over entire Visual Field, while BRAO results in focal Vision Loss
- May be preceded by prior episode of Amaurosis Fugax
- May be associated with other focal neurologic deficits
- See Transient Ischemic Attack
- Affects ipsilateral Carotid Artery circulation
- Signs
- Visual Acuity reduced to light perception
- Relative Afferent Pupillary Defect
- Pupil dilated with slow reaction
- Fundoscopic exam
- Retina appears pale-gray due to Retinal edema
- Macula with cherry-red spot on white-yellow background
- Constricted arterioles
- Box-Carring of Retinal vessels
- Retinal vessels with interrupted columns of blood appear as train box cars
- Hollenhorst Plaques (white punctate Cholesterol emboli)
- "Glistening orange yellow flakes"
- Represent fragmented emboli at arteriole bifurcations
- Neck Exam
- Differential Diagnosis
- Labs
- Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (cRP)
- Increased in Temporal Arteritis
- Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (cRP)
- Diagnostics
- Electrocardiogram
- Evaluate for Atrial Fibrillation
- Electrocardiogram
- Imaging: Obtain after acute stabilization (see management below)
- See Transient Ischemic Attack
- Evaluate as Transient Ischemic Attack or CVA (depending on deficits and timing)
- MRI Brain with Diffusion Weighted Imaging (CT misses "TIA" lesions) AND
- Evaluate Carotid Arteries: Carotid Ultrasound or Head and Neck CT Angiogram or MR Angiogram
- Echocardiogram
- Evaluate as performed in CVA and TIA
- Management
- Immediate Ophthalmology Consultation without delay
- Irreversible Vision Loss begins in the first 90-120 minutes
- Manage in similar fashion to a stroke protocol
- Lower Intraocular Pressure or dislodge Occlusion
- Lie patient supine with both Eyelids closed
- Ballot the eye: Apply intermittent pressure to eyeball
- Massage the globe with index fingers or each hand, then release suddenly
- Apply pressure in repeated cycles of 5-10 seconds on and 5 seconds off
- Perform for 20 cycles total or from 5-30 minutes
- Goal is to dislodge a thrombus
- Aqueous outflow increases with eye pressure
- Retinal perfusion increases with release of eye pressure
- Ocular Paracentesis
- Ophthalmologist aspirates 0.1 to 0.4 ml anterior chamber fluid via 27-30 gauge needle
- Goal to reduce Intraocular Pressure and shift the embolism distally
- Consider Hypercarbia
- Patient rebreathes into a paper bag for 10 minutes of each hour OR
- Inhalation of mix of 5% carbon dioxide and 95% oxygen
- Goal is to result in eye vessel vasodilation due to increased carbon dioxide concentrations
- Consider Aqueous Humor production strategies
- Mannitol 1 g/kg IV for 1 dose AND Acetazolamide 500 mg IV for 1 dose OR
- Acetazolamide 500 mg orally for 1 dose
- Consider hyperbaric oxygen
- Other measures that have been used (discuss with ophthalmology)
- Timolol maleate (0.5%) one drop topically
- Pilocarpine drops to eye
- Oral Nitroglycerin
- Pentoxifylline (Trental) three 600 mg tablets daily
- Laser arteriotomy
- Embolectomy
- Experimental or insufficient evidence to support
- Intraarterial Thrombolysis
- Cerebrovascular Management
- Approach as Transient Ischemic Attack
- Evaluate patients age <50 years old for Hypercoagulable state causes (e.g. Antiphospholipid Antibody Syndrome)
- Temporal Arteritis (ESR or CRP meet criteria)
- Start empiric Corticosteroids
- Temporal artery biopsy or Doppler Ultrasound
- Immediate Ophthalmology Consultation without delay
- Prognosis
- Vision Loss risk increases after 90 minutes (and esp. after 4 hours) of arterial Occlusion
- Spontaneous visual improvement may occur in first 7 days after onset
- Final Visual Acuity in affected eye <20/400
- References
- Hartmann (2016) Crit Dec Emerg Med 30(6): 3-11
- Sales, Patel and Patel (2019) Crit Dec Emerg Med 33(12): 3-13
- Beatty (2000) J Accident Emerg Med 17:324-9 [PubMed]
- Biousse (2018) Ophthalmology 125:1597-607 [PubMed]
- Gelston (2020) Am Fam Physician 102(9):539-45 [PubMed]
- Pokhrel (2007) Am Fam Physician 76:829-36 [PubMed]